1. Technical Field
The present disclosure relates to a display device and a method for driving the same.
2. Description of the Related Art
Display devices are often driven by using a hold-type drive method, which may cause motion blur, reducing dynamic image quality of the display devices. Referring to FIG. 11, the solid line represents an actual brightness curve of the display devices using the hold-type drive method, and the broken line represents a viewing brightness curve of the conventional display devices using the hold-type drive method. The frame rate can be set to be 60 Hz; however, the display devices generate motion blur due to the viewing brightness values superimposing with the actual brightness values shown on the solid line.
A pulse-type drive method is often used on the display devices to improve the motion blur. Referring to FIG. 12, the solid line represents an actual brightness curve of the conventional display panels using the pulse-type drive method, and the broken line represents a viewing brightness value of the display devices using the pulse-type drive method. The frame rate can be still set to be 60 Hz; the average brightness values viewed by the user are close to the actual brightness values of the display devices, thus the display devices do not result in motion blur.
The general pulse-type driver method mainly uses a so-called black insertion technology. A single frame can be separated into two or more consecutive and adjacent sub-frames by using the black insertion technology, in which the earlier sub-frame is a bright frame and the later sub-frame is a black frame corresponding to a black image. Also referring to FIG. 13, F(n), F(n+1), and F(n+2) represent three consecutive frames, among them, each frame corresponds to two sub-frames. For example, frame F(n) corresponds to sub-frames F(n)_1 and F(n)_2, frame F(n+1) corresponds to sub-frames F(n+1)_1 and F(n+1)_2, and frame F(n+2) corresponds to sub-frames F(n+2)_1 and F(n+2)_2, among them, F(n)_2, F(n+1)_2, and F(n+2)_2 are the black sub-frames in the black insertion technology.
FIG. 14 shows a schematic view illustrating brightness of all the frames and the sub-frames shown in the FIG. 12. Provided that the frame rates of the frames F(n), F(n+1), and F(n+2) are set as 60 Hz, then the frame rates of the sub-frames F(n)_1, F(n)_2, F(n+1)_1, F(n+1)_2, F(n+2)_1 and F(n+2)_2 are 120 Hz. The black sub-frames F(n)_2, F(n+1)_2, and F(n+2)_2 respectively have low brightness in their corresponding frames F(n), F(n+1), and F(n+2), so that each black sub-frame is inserted between two bright sub-frames. Thus, the display devise can display images with double frame rate and alternately dark and bright sub-frames, resulting in elimination of motion blur.
However, since the bright sub-frame and the black sub-frame as a single frame are displayed sequentially, there is an obvious brightness difference, namely flicker, on the screen. Thus, even though motion blur is eliminated, image quality is reduced due to flicker phenomenon.
What is needed, therefore, is a display device and a method for driving the display device, which can overcome the described limitations.